Abstract: The East China Accelerator Neutron Source (ECANS) is a comprehensive scientific research platform with extensive research and application needs in the field of nuclear technology applications. In order to design a high power electron linac for radioactive isotopes production, the paper first explored the parameter selection criteria for electron linac. The selection method was mainly based on the electron energy region with maximum photon generation efficiency. At the same time, based on mature high-power electron irradiation linac technology, the most cost-effective energy was selected as 35 MeV. There were two operating modes for the linac: long pulse mode and short pulse mode. The long pulse mode was used for radioactive isotopes production, neutron radiography, industrial irradiation, neutron activation analysis, and so on. The short pulse mode was mainly used for nuclear data measurement. Four energy operating states (7.5, 10, 12, and 35 MeV) were supported by the long pulse mode. For the long pulse, the pulse current intensity is about 250 mA, the maximum repetition frequency reaches 500 Hz, and the maximum average current intensity is 2 mA. For the short pulse, the pulse current intensity is about 750 mA, the maximum repetition frequency reaches 100 Hz, and the pulse time length is ranging from 10 to 100 ns. The electron linac was composed of three stages room temperature traveling wave accelerator tube. The first stage accelerates the electron up to 10 MeV. The 10 MeV electron beam is vertically deflected downwards by 90° using an α magnet for industrial irradiation. The 10 MeV electron beam can also be horizontally deflected 45° by a deflection magnet for electron beam experiments. The physical design scheme for the key components of the device was provided, including the physical design of the electron gun, accelerator tube, α magnet, target station, and other aspects. The 35 MeV electron beam was transported to the target station to produce X-ray and neutron. The target station consists of a tungsten target and a shielding body. There were two types of tungsten targets: the thin target and the thick target. The thin target employed in photon production has a yield of about 1.0×10¹⁶ s⁻¹. The thick target employed in neutron production has a yield of about 5.2×10¹³ s⁻¹. There are eight channels inside the shielding body for extracting photons and neutrons for experiments and applications. The length of neutron beamline is about 50 meters, which can provide excellent neutron energy resolution for neutron nuclear data measurement. This paper also presents the recent device commissioning outcomes, including the acceptance of a 10 MeV electron beam and a resulting 1 mA current at 35 MeV. This paper’s research can provide a multi-functional comprehensive scientific research platform in the field of nuclear technology application.